Screw gauge



April 1'4, 1953 D. E. STAINTON 2,634,508

I SCREW GAUGE Filed Feb. 13, 1948 v 2 lSl-IEETS-Sl-IEET 1 14, 1953 D. E. STAINTON 2,634,503

I SCREW GAUGE Filed Feb. 13, 1948 2 SI-EETS-SI-1EET 2 Patented Apr. 14, 1953 UNITED STATES PATENT OFFICE SCREW GAUGE Application February 13, 1948, Serial No. 8,231 In Great Britain October 9, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires October 9, 1963 mounted in said body portion and adapted to be projected into said aperture against the action of spring means one set of elements providing a go au e, and another set anot go gauge.

j, The screw gauge may comprise a body portion having an axial aperture, a circumferential series "of axially extending grooves, radial slideways connecting the grooves with the axial aperture, and accommodating sets of radially displaceable gauging elements having cross-pieces lying within the grooves, recesses in the body portion opening to the grooves and accommodating coil springs which engage the cross pieces to hold the gauging elements normally in their outer positions.

In the accompanying drawings:

Figure l is an end view of the gauge with the face plate removed,

Figure 2 is a side view of the body of the gauge,

Figure 3 is a cross section at 33 of Figure l with the face plate in position,

Figure 4 is a view of the end plate,

Figure 5 is an end elevation partly in section of a modification,

Figure 6 is a cross section on line 6-6 of Figure 5,

Figure 7 is a sectional elevation of the cam ring,

Figures 8 and 9 are views of a mounting for use in threading the gauging elements.

In carrying the invention into effect according to one convenient mode by way of example, see Figures 1 to 4, the gauge comprises a body member I which is provided with four slideways 2, 3, 4, 5. These slideways are arranged on diameters at right angles to one another and extend axially about one-half the length of the body I. At their inner ends the slideways 2, 3, 4 and 5 open into an axial bore 6 which extends throughout the body, at one end being chamfered at I. At their outer ends the slideways 2, 3, 4 and 5 open into peripheral grooves 8, 9, I0, I I which are substantially wider than the slideways. The grooves extend throughout the length of the body. The inner base walls of the grooves are arranged at right angles to the slideways.

6 Claims. (Cl. 33-199) Located within the slideways 2, 3, 4 and 5 and slidablethreinl are gauging elements, I2, l3, I4 and I5, the elements I2 and I3 co-operate to form say the fgo" gauge, while the elements I4 and I5 co-operate to form the not go gauge. Each gauging element is provided with a cross piece I6 all of which are of similar construction. The cross pieces I6 are accommodated within 'the grooves 8, 9, ID and II, and are secured to the gaugingelements by screws I! or in any other suitable way. The outer faces of the cross pieces conform to the circular shape of the body I.

Endwise movement 01 the'gauging elements is prevented by a cover plate I8 which is secu'red'to the body I by screws I9.

The cover plate is provided with a central aperture 20, chamfered on its exterior end, which conforms to and is in alignment with the aperturefi of the body I. The cover plate I8 is provided with pins 2| which overlie an edge on each gauging element and limit their outward movement.

Located within the body I and openin to the inner base Wall of the grooves 8, 9, III, II are recesses 22 which accommodate coil springs 23. These springs abut against the inner faces 24 of the cross pieces I6 whereby they ar normally thrust outward so that the inner gauging ends 25 of the gauging elements are located within the slideways and clear of the bore 6.

Inward movement of the gaugingelements to the gauging position is controlled by adjustable setting means. According to the preferred 3 arrangement each gauging element is provided with a pair of rotatable face cam washers 26 located on either side of the gauging element and secured to the body I by screws 21. The inclined cam faces 28 are adapted to be engaged by balls 30 secured in the cross piece I6. Clearance holes 29 are provided in the cross piece to enable the screws 21 to be operated when rotary adjustment of the cam washers 26 is required. The springs 23 and the cam washers 26 are obliquely disposed relatively to each other on opposite sides of each slideway.

The gauging faces 25 of the gauging elements are provided with appropriate threads according to the size of the gauge.

In operation, the gauge is passed over the screw to be tested and the gauging elements pressed inwardly by thumb and finger to bring the gauging faces into contact with the thread, the elementsbeing used in pairs for go and not go. In order to determine if the auging elements are at their respective gauging positions, sighting apertures 3| are provided in the cover plate I 8 by which it may readily be seen when the balls 30 are in contact with the cam washers thus providing both a feel and sight test.

The aperture 6 is adapted to serve as a plain ring gauge for the major diameter of the thread of the piece being tested and would thus reject threaded work whose major diameter is .above nominal size. It will be obvious that the aperture 6 may be of a diameter larger than the major diameter of the thread in which case-it would not serve as a gauging aperture.

The gauging elements may be prepared by being mounted in a threading fixture 32, see Figures 8 and 9, having a plurality of radial slots or recesses 33 in which the elements 34am fixed by an end cover plate 35. The elements 34 would all be threaded as "go or not go gauges and opposite elements would be utilised as pairs 'for inserting in the gauging body I.

According to a modified arrangement, see Figures 5, 6 and 7, the inward movement ofthe gauging elements l2, l3, l4 and I may be effected by a rotary cam ring 36 mounted on thebody 3'! between an end flange 38 and a cover plate 39.

The cam :ring is provided with a pair =.0f cam surfacesor grooves A0 for the g0 gauging elements 1!, l3 and an oppositely disposed and :operating-pair :o'f cam surfaces or grooves A! for q :the fnot-go gauging elements M, 15. The cam grooves co-operate with balls 42 mounted in the exterior surfaces of the gauging element bridge pieces 43. In order to mount the cam ring .36

.in position, the cam grooves 49, A! have axially or neutral position of the cam ring, "both pairs ofigauging elements are located fully within'their slideways leaving the major diameter aperture available for use.

'The .cam ring 36 is provided with apertures 59 for the insertion of a screw driverto adjust face-.cam stops 60 similar to those shown at .26 Figures :1, 2 and :3, and with which balls 31! on the bridge pieces 43 :are adapted to abut in a ggaug-ing operation.

:It will .be appreciatedthatrthe relative angular position of the cam-ringfifi-to'move the gauging elements .to their :correct gauging position will .be determined by the race cam steps '50.

.I .claim:

1. A limit screw ring gauge for testing go full .form and not :go effective diameters of screw rthreaded work :pieces, comprising :a body mounting-hf ring shape :having a central caper- :ture, a set of go gauging elements mounted in the body mountin :for radial displacement relatively thereto, said gauging elements having inner end gauging formations movable by said displacement into said central aperture against .the action :of spring means, said gauging elements beingangularly spaced around said body portion, a set of not go" gauging elements mounted inthe body portion for radial displacement relatively thereto, said not go gauging elements having inner end gauging formations movable by said displacement into said central aperture against the action of spring means, said 1 ring mounted on-the body mounting and surrounding the gauging elements, said elements beingprovided with balls ,on their outer extremities, said scam ring being provided with oppositely directed and operating cam surfaces adapted to engage the balls on the gauging elements, one set of cam surfaces cooperating with the balls on one set of gauging elements, the other set of cam surfaces cooperating with the balls on the other set of gauging elements.

'3. A limit screw ring gauge as claimed in claim .1, wherein :said means comprise surfaces operatively connected to the gauging elements and which are exposed to receive direct manual pressure .to displace the gauging elements radically inward.

A. A limit screw ring gauge as claimed in claim 3 wherein adjustable stop means, one for each gauging element are provided, for limiting the inward movementof the element, each of said stop means comprising an adjustable face cam mounted in the body mounting with which an abutment operatively connected to the gauging element engages when the element .is

moved to its inner gauging position.

5. A limit screw ring gauge for testing %go" full :form and not go effective diameter of screw threaded work pieces, comprising a body mounting having a central aperture, a circumierential series of axially extending grooves, :radial slideways connecting said grooves with said aperture, a set of go gauging elements mounted in alternate .slideways for .radial -dis-. placement therein, a set ;of ".not .go gauging elements mounted in theiremainings'lid'eways "for .radial displacement therein, said Jgaug'ing .elementshaving crosspieces locatedinsaid grooves, recesses in said body .mounting opening to the 0 BS, .coil springs in said recesses .and .engaging said cross ,pieces .to ,hold the gauging .ele- .ments in their outer positions, an vend -.cov er mounted on the body mounting to .close the ends of said slideways, projections in saidcover iorming retaining stops for limiting .the outward movement of said gauging elements, and means whereby each set of gauging elements .may be Jdisplacedinto their gaugingposition w'ithoutdisplacing the other set ofgaugingelemeiits;

6. A limit screw .ring gauge as claimed in claim 5 wherein inward .limit stops are provided for each gauging element comprising adjustable face rcam washers at the .bottom of .saidgrooves', and balls mounted on the cross pieces adapted to engage the cam ,iaces when the gauge element is moved to its gauging position.

DUDLEY ERNEST STAINTQLL' References .Cited in the file .01 this pa"t'ent UNITED STATES PATENTS Number Name Date 1,169,327 Hess Jan. 25, 1916 1,307,451 Parker June 24, 1919 1,630,690 B0518 May 31, 192'? 1,908,253 Johnson May 9,1933 1,949,971 Miller et al Mar. 6,1934 2,239,981 Terry et al.. Apr. 29,1941 2,249,954 Hellberg et a1 'Jli1y 22, 1941 2,356,133 V011 Kieboom Aug. '22, 194? 2,419,263 Hohwart 'Aprf22, 194 7 2,444,702 Johnson July 6,1948

FOREIGN PATENTS Number H Country .lDate 113,536 Great lBri-tain Feb. 28;:191'8 303,544 Germany "Feb. 5. 19:18 575,995 Great Britain Mar; 14,; 1945 

